<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 多个盒子都用了float，则并排一行，宽度超过网页宽度则排到下一行 */
        /* 高不同则是与最上边对齐 */
        .float1 {
            width: 300px;
            height: 200px;
            background-color: rgb(14, 243, 239);
            float: left;
        }

        .float2 {
            width: 300px;
            height: 300px;
            background-color: rgb(0, 255, 4);
            float: left;
        }

        .float3 {
            width: 300px;
            height: 200px;
            background-color: rgb(14, 243, 239);
            float: left;
        }
    </style>
</head>

<body>
    <div class="bot">
        <div class="float1">1</div>
        <div class="float2">2</div>
        <div class="float3">3</div>
    </div>
</body>

</html>